John Thomas (22 October 1736 – 27 March 1769) was a Welsh Anglican priest and antiquarian.
After studying at the Friars School in Bangor, he went to the University of Oxford, matriculating as a member of Jesus College in 1755.
He did so after spending some time as the under-keeper of the museum in Oxford before finding that his wages were inadequate to match his drinking.
In 1766, he was appointed as deputy to the master of Beaumaris grammar school, with curacies in Llansadwrn and Llandegfan.
He copied old Welsh language manuscripts, but his collection was dispersed after the death of his brother (Richard Thomas) who inherited them.